The present invention relates to rearview mirror assemblies and, more particularly, to a modular variable reflectance interior rearview mirror assembly for use in vehicles incorporating information displays and controls for various electronic or electrical functions.
Variable reflectance interior rearview mirror assemblies include two basic designs: Prismatic mirrors and electrochromic mirrors. Conventional prismatic mirror assemblies include a reflective element having a wedge shape in cross section and a mechanical actuator which moves the mirror case and reflective element between a day viewing position and a night viewing position. Typical mechanical actuators include a bracket pivotally mounted to the rear wall of the casing and a toggle which pivots the mirror case and reflective element with respect to the bracket. However, these actuators often exhibit rotational movement between the casing and the bracket which can lead to increased vibration in the casing and reflective element. With increased vibration, the reflection in the reflective element is blurred. In addition, space within the prismatic mirror casing is limited by the actuator which moves within the casing.
More recently, prismatic mirrors have incorporated a number of electronic and electrical devices within the interior rearview mirror assembly, for example lights for illuminating maps or the dashboard and, furthermore, information displays which provide information to the driver or occupants of the vehicle such as warnings relating to the status of the passenger airbag. In commonly assigned application Ser. No. 09/244,726, filed by Jonathan E. DeLine and Niall R. Lynam, on Feb. 5, 1999, now U.S. Pat. No. 6,172,613, information displays are provided which include information relating to vehicle or engine status, warning information, and the like such as information relating to oil pressure, fuel remaining, time, temperature, compass headings for vehicle direction, and the like, the disclosure of which is incorporated herein by reference in its entirety. With the increased number of devices desired to be housed in the mirror case and the increased number of functions provided by the various devices, maximizing space or making more efficient use of the available space is highly desirable. In addition, because of the increase in included devices as well as the number of combined features, the rearview mirror assembly process has become more difficult and complex.
Electrochromic mirror assemblies, on the other hand, include a variable reflectance element in the form of an electro-optic cell or unit in which reflectivity is changed in response to changes in light and the amount of electrical voltage applied across the cell/unit. Therefore, electrochromic mirrors do not require an actuator. As a result, the interior of the electrochromic mirror casing has more space for incorporating further electronic and electrical features, such as map reading lights, as noted above, blind spot detection systems, rain sensor assemblies, video cameras for actuating windshield wipers or other purposes, or receivers, such as remote keyless entry receivers, cellular phone receivers, microphones, and the like. Heretofore, electrochromic mirror designs have included mirror casings with structural reinforcement which provides support for the reflective element in the casing, support for additional electronic or electrical features, and stiffness to the casing. However, such reinforcements reduce the potential available space in the mirror casing.
In the interest of economy and ease of assembly, it is highly desirable to simplify the assembly process by having a common modular design for both electrochromic and prismatic mirror assemblies. Heretofore, the designs of the mirror casings of the electrochromic and prismatic mirror assemblies have had different internal structures which result from their different mounting arrangements. As the desire to place more devices and features in the casing has increased, the economy and efficiency use of space is taken on increased importance.
Consequently, there is a need for a rearview mirror structure which permits a wide range of electrical and electronic components to be housed in the mirror housing, and which uses a plurality of common components to assemble either electrochromic or prismatic mirror assemblies as desired. Such structure would enhance the economy of the mirror assembly and, furthermore, would provide a product familiar to consumers and users regardless of whether the consumer/user purchases a prismatic or electrochromic mirror assembly.